Maria was the wife of Frank Castle. She was a loving wife and good mother of their two children. Disaster struck when Maria, Frank and the kids went for a picknick in Central Park. There they where witnesses to a mob execution. During this time, the mob fired on the family as well, fatally hitting Maria and her children. Frank was also gunned down but survived. These events and the death of Maria and his kids where the trigger for Frank Castle to become the Punisher.
Maria Castle was created by Gerry Conway and Tony DeZuniga and first appeared in the black and white magazine known as Marvel Preview Issue #2 (1975), that depicts the origin of the Punisher for the first time.
Major Story Arcs
In Dark Reign, The Punisher was gunning after Norman Osborn. He decided to take down The Hood. This decision did not turn out well for Frank. Frank soon found that The Hood was working with Frank's old partner, Microchip, and that Microchip had allied himself with The Hood for two reasons; one, he owed The Hood for bringing him back, and two, The Hood promised to resurrect his dead son.
Eventually Frank's crusade came down to a final standoff. Microchip, Frank, The Hood, and the corpses of Frank's family and Microchip's son gathered. All Micro had to do to resurrect his son and Frank's family - according to The Hood's rules - was kill a SHIELD agent. Micro dutifully obliged, and Frank was horrified to watch as the caskets of his dead family opened once more.
Frank then grabbed a flamethrower from a recently resurrected The Hood had sent after him, and burnt his family and Micro's son alive, knowing that they were meant to be dead.
In The Blood
After Frank's ordeal as the 'Franken-castle', he returned to New York. He decided to go after Microchip, as he couldn't find The Hood. He fought a mysterious woman in black leather with burnt skin, who called him "Angel". Maria had been kept alive after her resurrection - Frank's attempt at burning her to death failed.
Or so Frank thought. It turns out that the woman who claimed to be Maria was actually Lady Gorgon, an assassin who Frank had once burned alive, and who'd now been hired by Jigsaw to play with Frank's head. When Frank finds this out, he kills her.
Maria appears in the MAX version of the Punisher.
The Punisher (2004)
In the 2004 film, Maria Castle was played by actress Samantha Mathis.